A system is identified as an MCC
based on its characteristics as depicted on IR
satellite imagery.

The physical characteristics
include a general cloud shield with continuously
low IR temperatures less than -32° C over an
area 100,000 km2, with an interior
cold cloud region with temperatures less than
-52° C having an area of 50,000 km2.

MCCs often last for 6-12 h, and
are especially known for producing heavy amounts
of rain, although severe winds, hail, and
tornadoes can also occur during the early phases
of MCC evolution.